At least when I got married, all I needed was a passport and a potential wife.
Then also my wife was my attorney, and I am just a dumb gringo. There might have been whole lot more to it, that I will never know.
Seriously however you might want to talk to an attorney. You want to make sure you get the right type of marriage. There are several kinds in Chile, and the wrong one can turn your life in to a paperwork hell doing anything official. The most common, such as you would think of in most other countries would be the complete separation of assets. There is another one that the husband is in complete control of the marriage assets, and another one where the wife has to sign off on everything. Again, talk to an attorney to get all the gory details.